For the purposes of the present patent application, an electrical plug and an electrical plug receptacle are electrical components which are intended on the one hand to be firmly or permanently connected to a cable and on the other hand to form a preferably detachable plug-and-socket connection with a mating component. Here, the mating component of the plug is designated plug receptacle and the mating component of the plug receptacle is designated plug. The plug is preferably a separate component, which serves solely to connect the cable with a plug receptacle. The plug receptacle may, on the other hand, also be incorporated into a housing of any desired apparatus. This may alternatively also be the case for the plug.
In engineering and in particular in electrical engineering, a large number of plugs and plug receptacles of many different types are known. These serve to transmit electrical power and/or electrical signals with the widest possible range of voltages, currents, frequencies and data rates. Furthermore, plug and plug receptacle fulfill other functions. For damp, dusty or chemically aggressive environments, plugs and plug receptacles comprise sealing elements which prevent penetration of the surrounding media into the plug and plug receptacle and corrosion thereof or the formation of conductive deposits therein. Securing elements such as screw threads or latches ensure a secure plug-and-socket connection, even if the plug-and-socket connection is exposed to mechanical tension or vibrations.
Due to the extremely wide range of applications and conditions of use, a wide variety of optimized plugs and plug receptacles are to be found.
A relatively new field of use for plugs and plug receptacles is the transmission of drive power in an electrically driven motor vehicle. This drive power has to be transmitted between an energy storage means, for example a storage battery or a fuel cell, and a power converter, for example a four-quadrant converter, and between the latter and the drive motor(s) in one direction or in both directions alternately. Between the energy storage means and the power converter, the electrical power is transmitted substantially in the form of d.c. voltage and a direct current. Between the power converter and the drive motors, the electrical power is transmitted for example in the form of a three-phase current. Conversion in the power converter may occur by means of pulse width modulation. The a.c. voltage and alternating current component, in particular on transmission of the power between the power converter and motors, may lead to the emission of electromagnetic interference signals, which may disturb other electrical and electronic systems inside and outside the vehicle. The emission of interference signals is prevented by providing the lines via which the electrical power is transmitted with shielding. This ensures electromagnetic compatibility (EMC) and minimizes the risk of harm to the health of individuals in the surrounding area.
Motor vehicles with an electromotive drive existed until recently only in the form of prototypes or short run models. For this reason, the plugs and plug receptacles which have been used in the power transmission area are those which are readily available but are distinguished for the most part by a robust but also very complex structure. These plugs and plug receptacles are therefore complex and expensive to produce and fit.
With electrically driven motor vehicles moving into the realms of series and mass production, the demands placed on the plugs and plug receptacles in the power transmission area are also changing. They not only have to be robust and ensure long-term, malfunction-free functioning over the entire life of the motor vehicle but also have to be simple and cheap to produce and fit.